CVE-2019-1756

CVE-2019-1756 is a high-severity vulnerability in Cisco Ios with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-20.

Key facts

Description

A vulnerability in Cisco IOS XE Software could allow an authenticated, remote attacker to execute commands on the underlying Linux shell of an affected device with root privileges. The vulnerability occurs because the affected software improperly sanitizes user-supplied input. An attacker who has valid administrator access to an affected device could exploit this vulnerability by supplying a username with a malicious payload in the web UI and subsequently making a request to a specific endpoint in the web UI. A successful exploit could allow the attacker to run arbitrary commands as the root user, allowing complete compromise of the system.

Frequently asked questions

What is CVE-2019-1756?
A vulnerability in Cisco IOS XE Software could allow an authenticated, remote attacker to execute commands on the underlying Linux shell of an affected device with root privileges. The vulnerability occurs because the affected software improperly sanitizes user-supplied input. An attacker who has valid administrator access to an affected device could exploit this vulnerability by supplying a username with a malicious payload in the web UI and subsequently making a request to a specific endpoint in the web UI. A successful exploit could allow the attacker to run arbitrary commands as the root user, allowing complete compromise of the system.
How severe is CVE-2019-1756?
CVE-2019-1756 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2019-1756 being actively exploited?
It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 4% (89th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2019-1756?
CVE-2019-1756 primarily affects Cisco Ios. In total, 16 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2019-1756?
Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2019-1756 published?
CVE-2019-1756 was published on 2019-03-28 and last updated on 2026-06-17.

References

Affected products (16)

More vulnerabilities in Cisco Ios

All CVEs affecting Cisco Ios →

Other CWE-20 (Improper Input Validation) vulnerabilities

Browse all CWE-20 (Improper Input Validation) vulnerabilities →